Support is requested for a Keystone Symposia meeting entitled The Ins and Outs of Viral Infection: Entry, Assembly, Exit and Spread, organized by Karla Kirkegaard, Mavis Agbandje-McKenna and Eric O. Freed. The meeting will be held in Breckenridge, Colorado from March 30 - April 4, 2014. Viruses can enter cells by mechanisms such as the classic virus-receptor interactions, cell-cell fusion and newly observed pathways that are currently being investigated. Similarly, viral exit from infected cells can follo the paradigms of cell lysis or viral budding, but new mechanisms such as unconventional secretion and exosome formation are emerging. Viruses in the process of entering or exiting cells should be especially vulnerable to antivirals because of their accessibility and because the formation of oligomeric structures that mix drug-susceptible and drug-resistant capsids can suppress the emergence of drug-resistant viruses. However, these steps are more difficult to target biochemically due to the lack of readily assayed enzymatic activity. This meeting will bring together structural biologists, geneticists, cell biologists and mathematic modelers to address the mechanisms and consequences of the different modes of viral travel. Thus, the program for this meeting is highly likely to attract a wide variety of investigators, many of whom might not otherwise interact.